From 0ddb7ea842abf63516b74d4b057c052afc6ba863 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 28 Feb 2019 11:33:22 -0300 Subject: nptl: Assume __ASSUME_FUTEX_CLOCK_REALTIME support This patch assumes realtime clock support for nptl and thus removes all the associated code. For __pthread_mutex_timedlock the fallback usage for the case where lll_futex_timed_wait_bitset it not set define is also removed. The generic lowlevellock-futex.h always define it, so for NPTL code the check always yield true. Checked on x86_64-linux-gnu and i686-linux-gnu. * nptl/nptl-init.c (__have_futex_clock_realtime, __have_futex_clock_realtime): Remove definition. (__pthread_initialize_minimal_internal): Remove FUTEX_CLOCK_REALTIME check test for !__ASSUME_FUTEX_CLOCK_REALTIME. * nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock): Assume __ASSUME_FUTEX_CLOCK_REALTIME support. * sysdeps/unix/sysv/linux/i386/lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_FUTEX_CLOCK_REALTIME): Remove. * sysdeps/nptl/lowlevellock-futex.h (lll_futex_timed_wait_bitset): Adjust comment. --- nptl/nptl-init.c | 29 ----------------------------- nptl/pthread_mutex_timedlock.c | 27 --------------------------- 2 files changed, 56 deletions(-) (limited to 'nptl') diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c index b5895fa..61ec8ed 100644 --- a/nptl/nptl-init.c +++ b/nptl/nptl-init.c @@ -58,15 +58,6 @@ int __set_robust_list_avail; # define set_robust_list_not_avail() do { } while (0) #endif -#ifndef __ASSUME_FUTEX_CLOCK_REALTIME -/* Nonzero if we do not have FUTEX_CLOCK_REALTIME. */ -int __have_futex_clock_realtime; -# define __set_futex_clock_realtime() \ - __have_futex_clock_realtime = 1 -#else -#define __set_futex_clock_realtime() do { } while (0) -#endif - /* Version of the library, used in libthread_db to detect mismatches. */ static const char nptl_version[] __attribute_used__ = VERSION; @@ -298,26 +289,6 @@ __pthread_initialize_minimal_internal (void) set_robust_list_not_avail (); } -#ifdef __NR_futex -# ifndef __ASSUME_FUTEX_CLOCK_REALTIME - { - int word = 0; - /* NB: the syscall actually takes six parameters. The last is the - bit mask. But since we will not actually wait at all the value - is irrelevant. Given that passing six parameters is difficult - on some architectures we just pass whatever random value the - calling convention calls for to the kernel. It causes no harm. */ - INTERNAL_SYSCALL_DECL (err); - word = INTERNAL_SYSCALL (futex, err, 5, &word, - FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME - | FUTEX_PRIVATE_FLAG, 1, NULL, 0); - assert (INTERNAL_SYSCALL_ERROR_P (word, err)); - if (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS) - __set_futex_clock_realtime (); - } -# endif -#endif - /* Set initial thread's stack block from 0 up to __libc_stack_end. It will be bigger than it actually is, but for unwind.c/pt-longjmp.c purposes this is good enough. */ diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c index 2f61a7d..270b072 100644 --- a/nptl/pthread_mutex_timedlock.c +++ b/nptl/pthread_mutex_timedlock.c @@ -240,27 +240,6 @@ __pthread_mutex_timedlock (pthread_mutex_t *mutex, values despite them being valid. */ if (__glibc_unlikely (abstime->tv_sec < 0)) return ETIMEDOUT; -#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ - || !defined lll_futex_timed_wait_bitset) - struct timeval tv; - struct timespec rt; - - /* Get the current time. */ - (void) __gettimeofday (&tv, NULL); - - /* Compute relative timeout. */ - rt.tv_sec = abstime->tv_sec - tv.tv_sec; - rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; - if (rt.tv_nsec < 0) - { - rt.tv_nsec += 1000000000; - --rt.tv_sec; - } - - /* Already timed out? */ - if (rt.tv_sec < 0) - return ETIMEDOUT; -#endif /* We cannot acquire the mutex nor has its owner died. Thus, try to block using futexes. Set FUTEX_WAITERS if necessary so that @@ -287,18 +266,12 @@ __pthread_mutex_timedlock (pthread_mutex_t *mutex, assume_other_futex_waiters |= FUTEX_WAITERS; /* Block using the futex. */ -#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ - || !defined lll_futex_timed_wait_bitset) - lll_futex_timed_wait (&mutex->__data.__lock, oldval, - &rt, PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); -#else int err = lll_futex_timed_wait_bitset (&mutex->__data.__lock, oldval, abstime, FUTEX_CLOCK_REALTIME, PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); /* The futex call timed out. */ if (err == -ETIMEDOUT) return -err; -#endif /* Reload current lock value. */ oldval = mutex->__data.__lock; } -- cgit v1.1